Abstract
Since the cost of gallium arsenide(GaAs) substrate is expensive, core-shell GaAs nanowires(NWs), which used to be grown on GaAs substrate, had turned to be grown on silicon(Si) substrate via the self-catalyzed mechanism in recent years. In order to make a solar cell device, core-shell GaAs NWs must produce one insulator layer between top electrode and substrate to prevent short-circuiting. However, we still cannot find a decent solution for it. Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) is currently one of the most promising conducting polymers, which has great formation of p-n junction with both GaAs and Si. This could solve the short-circuiting problem between top electrode and silicon substrate. In this study, we use PEDOT:PSS as a P-type semiconductor material to replace the shell layer in core-shell structure. PEDOT:PSS thin film were spin coated on GaAs NWs and indium tin oxide conductive glass. Afterwards, the nanowire set were pressed onto the conductive glass to fabricate the GaAs/PEDOT:PSS hybrid solar cell device. We discussed the effect of the nanowire length, diameter and spin coating speed on the optical properties of nanowire devices. The best power conversion efficiency in our work is 4.58 x 10-3%.